It might cut down on the volumes of resumes, but once culled down to actual potentials, I think the effect of the "niche language" is minimal. I spend my time hopping between a bunch of languages and I'm equally mediocre in all of them, but my friend who does the same is amazing in whatever language is thrown at him. I have yet to meet a really excellent programmer that can only program in one language (they might not be equally proficient in all of them).
When hiring for the small percentage of excellent programmers, I don't see language as a barrier. Sure, there will be spin up time, but you'll have that regardless. No one is experienced with every library, framework, or configuration. Adding in a new syntax might compound the issue, but I think that there is the definite potential for long-term productivity gains once the team is up to speed.
When hiring for the small percentage of excellent programmers, I don't see language as a barrier. Sure, there will be spin up time, but you'll have that regardless. No one is experienced with every library, framework, or configuration. Adding in a new syntax might compound the issue, but I think that there is the definite potential for long-term productivity gains once the team is up to speed.